Re: [patch] sawfish.wm.util.prompt

[Teika Kazura <teika lavabit com>]

Hi, all.

It's true that librep byte-compiler is buggy, as Timo said. Let me 
explain. 

First case:
------------------------------------------------------------------------
;; 1st
(define-structure sawfish.wm.compiler-bug
    (export )
    (open rep )

  (define (outer)
    (define (double arg)
      arg)

    (define (inner)
      (double t)
      )
    (inner)
    )
  )
-------------------------------------------------------------------------
Let's see what happens on (double), one by one. It is defined inside
of (outer). In this case, Compiler says nothing. OK.

------------------------------------------------------------------------
;; 2nd
(define-structure sawfish.wm.compiler-bug
    (export )
    (open rep )

  (define (double)
    t)

  (define (outer)
    (define (double arg)
      arg)

    (double t)
    )
  )
------------------------------------------------------------------------
In this case, (double) is two-fold. Inside of (outer), the inner
definition is used. Compiler says nothing. OK.

Now, I'll pull out a rabbit from the hat.
------------------------------------------------------------------------
;; 3rd
(define-structure sawfish.wm.compiler-bug
    (export )
    (open rep )

  (define (double)
    t)

  (define (outer)
    (define (double arg)
      arg)

    (define (inner)
      (double t)
      )
    (inner)
    )
  )
------------------------------------------------------------------------
What's the difference? (double) is now called inside of (inner).
Because (inner) is defined inside of (outer), it should use the
inner definition of (double).

But in this case, compiler warns:
 bug.jl:14: In function `outer':
 bug.jl:14: warning: too many arguments to `double' (1 given, 0 used)

The code should be ok. So it's a compiler bug.

If you liked my magic show, now let me offer you a dove:
------------------------------------------------------------------------
;; 4th
(define-structure sawfish.wm.compiler-bug
    (export )
    (open rep )

  (define (double)
    t)

  (define (ok-func)
    t)

  (define (outer)
    (define (double arg)
      arg)
    (define (ok-func arg)
      arg)

    (define (inner)
      (double t)
      )
    (inner)
    (ok-func t))

  )
------------------------------------------------------------------------
Now, (ok-func) is added. Compiler says:
 bug.jl:19: In function `outer':
 bug.jl:19: warning: too many arguments to `double' (1 given, 0 used)
 bug.jl:22: warning: too many arguments to `ok-func' (1 given, 0 used)

Please compare it to (double) in 2nd example. It's defined in the same
manner, and it used to be ok. But (double) has confused the compiler
to shift its policy; call to (ok-func) is declared to be illegal.
I hope that it's only the byte compiler, not the execution. The
4th example looks quiet nasty.

I don't know if what I've displayed here is related to prompt[-*].jl
problem, but remember, there *is* a bug(s).

Now, dear Sawfish lovers, it's really welcome to show that librep is
buggy, and to exhibit exactly how it turns us down. If it gets rid of
an issue of real problem, then it's good. But
On Sat, 19 Sep 2009 18:59:28 +0300, Timo Korvola wrote:
> The original code looks fine to me.

So, the simplest solution will be to go back to the original one.
Remember that we're in short of developers. Please use your energy to
actually improve Sawfish, and don't get stuck on aesthetics.

I'm sorry for being lazy, staying away form your discussions. I've
been aware of the problem, but I've deffered the analysis until
today. (One reason for my truancy is that your arguments level is
higher than my understandings. I don't know lisp well. I've never
understood fluid ;)

Thank you Matthew, Jeremy, Chris and Timo for your sincerity.

# I wonder if someone could summarize the util.prompt discussion.

With best regards,
Teika (Teika kazura)